It is known that certain tertiary amines can be treated with ozone to produce amine oxides and that under some conditions secondary amines are formed. A copending application of Applicant Arnold Hershman, Ser. No. 465,976, filed May 1, 1974, and now U.S. Pat. No. 3,969,398 concerns a process employing molecular oxygen-containing gas and activated carbon catalyst to remove an acetic acid group from N-phosphonomethylimino diacetic acid.